What kind of activities might you do in the evenings or at weekends?

I’m just out of a relationship, and part of the break-up coping strategy is to do lots of stuff. I do see friends pretty regularly, but they have their own lives and can’t keep me company all the time. I’m in the middle of a meditation course, which I’m loving, and have done some conservation volunteering. But everything else I can think of to do seems to cost tons of money which I just don’t have – which probably isn’t helped by living in London where everything is mega expensive by default. Any ideas for cheap/free things that might fill up an evening or weekend?